Facilitating effect of histamine on spatial memory deficits induced by dizocilpine as evaluated by 8-arm radial maze in SD rats

【摘要】 <正> AIM: To investigate whether or not histamine is involved in spatial memory deficits induced by dizocilpine （MK-801） as evaluated by 8-arm radial maze of rats. METHODS: 8-Arm （4-arm baited） radial maze was used to measure spatial memory in rats. RESULTS: Bilaterally intrahippocampal （ih） injection of MK-801 （0.3 μg/site） impaired working memory and reference memory in rats. Both histamine （50, 100 ng/site, ih） and intraperitoneal （ip） injection of histidine （100, 200 mg/kg） markedly improved the spatial memory deficits induced by MK-801. On the other hand, the ameliorating effect of histidine （100 mg/kg, ip） was completely antagonized by α-fluoromethylhistidine （α-FMH, 5 μg/site, ih）, a potent and selective histidine decarboxylase （HDC） inhibitor, and H₁-antagonist pyrilamine （1 μg/site, ih）, but not by H₂-antagonist cimetidine, even at a high dose （2.5 μg/site, ih）. CONCLUSION: The hippocampal histamine plays an important role in the ameliorating effect on MK-801-induced spatial memory deficits,更多还原

【Abstract】 AIM: To investigate whether or not histamine is involved in spatial memory deficits induced by dizocilpine （MK-801） as evaluated by 8-arm radial maze of rats. METHODS: 8-Arm （4-arm baited） radial maze was used to measure spatial memory in rats. RESULTS: Bilaterally intrahippocampal （ih） injection of MK-801 （0.3 μg/site） impaired working memory and reference memory in rats. Both histamine （50, 100 ng/site, ih） and intraperitoneal （ip） injection of histidine （100, 200 mg/kg） markedly improved the spatial memory deficits induced by MK-801. On the other hand, the ameliorating effect of histidine （100 mg/kg, ip） was completely antagonized by α-fluoromethylhistidine （α-FMH, 5 μg/site, ih）, a potent and selective histidine decarboxylase （HDC） inhibitor, and H₁-antagonist pyrilamine （1 μg/site, ih）, but not by H₂-antagonist cimetidine, even at a high dose （2.5 μg/site, ih）. CONCLUSION: The hippocampal histamine plays an important role in the ameliorating effect on MK-801-induced spatial memory deficits, and its action is mediated through postsynaptic H₁-receptor.更多还原